[RE-wrenches] 24 vs. 48

[Mark Frye]

Interesting.

I can choose an OB VFX3524 w/ 85 ADC or an OB VFX3648 w/ 45 ADC of charging
capacity.

And assuming that I need C/10 during bulk charging (and the importance of
this is really what I am asking about) then:

VFX3524: 85 ADC * 10 = 850 AH * 24 VDC = 20.4 kWH battery bank

VFX3648: 45 ADC * 10 = 450 AH * 48 VDC = 21.6 kWH battery bank

OK, so it's about a wash either way in terms of stored energy.

But assuming for the moment that distances are short and the initial
difference in copper costs are small, wouldn't you rather have half the
number of individual cells to maintain...less watering, less SG measuring,
lower overall "part" (individual 2V cells) count?
 
Mark Frye
Berkeley Solar Electric Systems
303 Redbud Way
Nevada City,  CA 95959
(530) 401-8024
www.berkeleysolar.com 

-----Original Message-----
From: re-wrenches-bounces at lists.re-wrenches.org
[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of R Ray
Walters
Sent: Tuesday, January 17, 2012 10:38 AM
To: RE-wrenches
Subject: Re: [RE-wrenches] 24 vs. 48

The only advantages of 24 v are that you can create smaller KWH battery
banks, and that Bergey's XL.1 was only available in 24 v.
Anytime the design allows, I jump to 48 v.

R. Walters
ray at solarray.com
Solar Engineer




On Jan 17, 2012, at 11:11 AM, Nathan Jones wrote:

> 
> 
> Mark,
> It would seem to be a wash. As the voltage is halved the amperage is
doubled in the battery bank. This would seem to require doubling the
charging amperage so nothing is gained. On a system of any size the 48 volt
gets the default nod here. Charge controllers handle twice the solar.
Parallel battery strings are eliminated, or at least held to two. Wire
sizing might be reduced on the low voltage side of things. And much easier
future expansion possibilities, too.
> Cheers,
> Nathan Jones
> Power Source Solar Inc
> 
> 
> ------------------------------
> On Tue, Jan 17, 2012 10:56 AM CST Mark Frye wrote:
> 
>> Not really on topic to Jay's question, but...
>> 
>> Is 48v always better than 24v?
>> 
>> How important is bulk charging current to overall battery life?
>> 
>> In some cases, isn't it better to use a 24v inverter/charger which 
>> can develop a higher charge current for a battery bank that has a 
>> higher AH rating?
>> 
>> Mark Frye
>> Berkeley Solar Electric Systems
>> 303 Redbud Way
>> Nevada City,  CA 95959
>> (530) 401-8024
>> www.berkeleysolar.com
>> 
>> -----Original Message-----
>> From: re-wrenches-bounces at lists.re-wrenches.org
>> [mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of jay 
>> peltz
>> Sent: Tuesday, January 17, 2012 8:43 AM
>> To: RE-wrenches
>> Subject: [RE-wrenches] battery buss bars
>> 
>> Hi All,
>> 
>> Where do I find buss bars for a battery parallel problem?
>> 
>> I've got to fix a brand new ( not me) system, that has 4 sets of 
>> L-16's at 24v.
>> Yea yea why didn't they go to 48?
>> 
>> So I want to use buss bars to parallel them, and looking for premade
ones.
>> 
>> Thanks in advance,
>> 
>> Jay
>> 
>> Peltz power
>> 
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